Sceye HAPS launch to Japan: 200-foot solar platform in August

Sceye will send a roughly 200-foot, solar-powered high-altitude platform station across the Pacific in August to park about 18 kilometers above the ocean and test supplementing Softbank’s 5G network, including beaming data straight to devices. The New Mexico–based firm plans to use a custom-built antenna mounted on the helium-filled craft to run the trial over the coast of Japan.

How will the Sceye platform work?

The platform is an oblong, helium-filled craft about 200 feet long, covered in lightweight reflective fabric, fitted with solar panels, batteries for stored energy, a custom antenna and an electric fan for station-keeping. The craft must soak up and store enough solar power during the day to provide around-the-clock power to that fan and the onboard systems, a design tradeoff Sceye says it proved in a 2024 test flight.

Sceye’s CEO and founder Mikkel Vestergaard Frandsen frames the approach as offering “space-like conditions, without the cost of going to space and without the complexity of being in orbit.” In a spring flight the firm kept the craft aloft for 12 days, flew to the coast of Brazil and spent more than 88 hours parked in various locations, demonstrating multi-day endurance and the ability to hold position for extended periods.

Why put internet equipment in the stratosphere?

The stratosphere lets a single platform cover a very large area while remaining much closer to the ground than even the lowest-orbiting satellites, which reduces the energy needed to send a signal down. Sceye plans to park its craft roughly 18 kilometers above the ocean to leverage those range and power advantages while using solar energy to run communications hardware.

That altitude and persistent presence make HAPS attractive for tasks that need wide coverage but lower latency and power than satellites: disaster-area communications, persistent observation of Earth’s surface, and mobile-network augmentation. Sceye and other HAPS builders argue the lower energy cost per downlink and the absence of orbital complexity are core benefits compared with satellites.

Who else is building HAPS and what are the use cases?

Sceye is among several companies developing airborne platforms known as HAPS, including an Airbus subsidiary called Aalto. HAPS platforms can be planes, balloons or oblong helium vehicles outfitted with solar panels. Industry plans include delivering internet service to disaster sites, observing Earth’s surface and supporting existing satellite networks; Sceye expects its platform could help satellite operators better serve densely populated areas.

The upcoming Softbank trial is explicitly a test of a HAPS serving as a supplement to a terrestrial 5G network and a trial of direct-to-device transmission from a stratospheric platform. That combination—mobile carrier partnership plus device-level links—will be a practical test of whether a HAPS can integrate with existing networks and customers.

Why it matters

A successful August flight would demonstrate a potentially cheaper, lower-energy alternative to some satellite services while avoiding orbital complexity. Carriers such as Softbank could use HAPS to fill coverage gaps, provide rapid disaster relief connectivity, or offload traffic in crowded regions without launching new satellites. The technical constraint—balancing extreme lightness with enough strength and stored solar energy to maintain station-keeping—remains Sceye’s chief engineering challenge.

What to watch

The key milestone is the August Pacific crossing and the platform’s ability to park at about 18 kilometers above the Japanese coast while beaming data directly to devices. Concrete signals of success will be sustained, around-the-clock power for the electric fan and communications hardware, and verified integration with Softbank’s 5G network during the test.